The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
The present disclosure pertains to a catalytic process for the ammoximation of carbonyl compounds to form oximes using a catalyst.
Oximes, in general, are important chemical intermediates. A particularly important component in this respect is cyclohexanone oxime, which is a precursor for ε-caprolactam, the monomer for nylon-6. Other important oximes include cyclododecanone oxime, salicylaldoxime, and acetophenone oxime.
Processes for ammoximation of carbonyl compounds in the liquid phase using a catalyst are known in the art.
For example, U.S. Pat. No. 4,745,221 describes a catalytic process for preparing cyclohexanone oxime by reacting cyclohexanone with NH3 and H2O2 in the liquid phase in the presence of a catalyst comprising titanium-silicalite.
EP347926 describes a catalytic process for the manufacture of oximes from carbonyl compounds using as catalyst a solid composition consisting of silicon, titanium, and oxygen, which composition is an amorphous solid. The best results are obtained when the reaction is carried out in t-butanol or cyclohexanol.
There are disadvantages associated with the processes described in these references. In the first place, titanium silicalite is a specialty chemical requiring a specified synthesis route which is complex and difficult. t-Butanol and cyclohexanol are less attractive as solvents from an environmental point of view.